Gas burner control system



May 4, 1965 A. KRAJC ETAL GAS BURNER CONTROL SYSTEM 2 Sheets-Sheet 1 Filed 001;. '7, 1963 y 4, 1965 A. KRAJC ETAL 3,181,592

GAS BURNER CONTROL SYSTEM Filed Oct. 7, 1963 2 Sheets-Sheet 2 /4 F1 15 4? NW 1.? a T w 10 r 1 I H 62 25L 5 2. 4 I 35 3.9

4/ 43 l/VVE/VTORS 22/ I, i000 k Pfidd United States Patent Office 3,181,592 Patented May 4, 1965 12 Ciaims. at. 158-4124) The present invention concerns a gas burner control system, and more particularly a control system which permits remote control of starting and terminating the operation of a burner, and also includes safety devices which prevent escape of gas from the burner in the absence of combustion.

Arrangements of this general type are known which comprise a gas control body having an inlet for the gas supply, a first outlet connectable to the main gas burner and a second outlet connected to a pilot flame gas burner and containing a main gas valve for controlling the flow of gas to the main burner and a pilot flame gas valve for controlling the flow of gas to the pilot flame burner. In addition, there is a housing combined with the gas control body and containing electrical and mechanical control devices for actuating the valves and also causing ignition of the pilot flame.

More particularly, the known arrangements also comprise a solenoid valve acting as the above-mentioned main gas valve and requiring a rather involved electrical control system.

It has been found that the use of a solenoid valve in a gas burner control system entails rather high cost in view of the solenoid valve itself and the related and necessary circuitry.

It is therefore one object of the invention to provide for a gas burner control system which operates entirely satisfactory in every respect and under any conditions but does not require the use of a solenoid valve.

It is another object of this invention to provide for a control system as mentioned above which is rather simple in construction and yet entirely reliable in operation.

With the above objects in view a gas burner control system according to the invention comprises, in combination gas inlet means; a main gas burner means; a main gas valve arranged between said gas inlet means and said main gas burner means for controlling the flow of gas to the latter; pilot flame gas burner means adjacent to said main gas burner means; a pilot flame gas valve arranged between said gas inlet means and said pilot flame gas burner means for controlling the flow of gas to the latter; electrical igniting means including ignitor means adjacent to said pilot flame gas burner means for igniting a pilot flame when said igniting means are energized while gas flows through said pilot flame gas valve to said I pilot flame gas burner means, and energizing means for energizing said ignitor means; electric valve control means including electromagnet means for holding when energized said pilot flame gase valve in open position once the latter has been moved to open position, and thermoelectric means responding to exposure to the heat of said pilot flame by energizing said electromagnet means so as to hold said pilot flame gas valve open as long as there is a pilot flame; and control means for controlling said main gas valve and said pilot flame gas valve and said igniting means, including electromotor means, motor switch means in circuit with said electromotor means for controlling the latter, switch means in circuit with said ignitng means for controlling the latter, rotary cam means rotatable by said electromotor means and actuating in different rotational positions said motor and ignition switch means, respectively, a mechanical actuating member cooperating with both said main gas valve and said pilot flame gas valve and movable by said electromotor means between a plurality of positions, in one of which said actuating member places both said main gas valve and said pilot flame gas valve in closed position, in a second one of which said actuating member places said pilot flame gas valve in open position while leaving said main gas valve closed, and in a third one of which said actuating member places both said main gas valve and said pilot flame gas valve in open position.

It will be seen from the description further below that the control system according to the invention has many advantages over the prior art. One of these advantages is also due to the fact that the valves used in the system can be arranged in such a manner that the gas pressure coming from the mains and acting on the valve tends to close or to keep closed the valves and does not counteract the resilient means which are provided for urging the valves at all times toward a closed position thereof. In addition to the elimination of the conventional solenoid valve the arrangement according to the invention makes it possible to arrange a comparatively small number of elements within the gas control body of the system. The entire arrangement can be constructed easily in such a manner that it requires comparatively small space and can be mounted without any difliculty within conventional gas-operated heating devices of any kind.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method or" operation together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a diagrammatic illustration of a gas burner control system according to the invention, all movable members thereof being shown in idle position;

FIG. 2 is a similar diagrammatic illustration, the movable elements thereof being shown in the position which they assmue when the operation of the system is started;

FIG. 3 is another diagrammatic illustration of the same system, the moving elements thereof being shown in the position which they assume while the main gas burner is in operation; and

FIG. 4 is a diagrammatic, cross-sectional elevation of a control system according to the invention, some portions of the electrical equipment thereof being omitted for the sake of clarity.

The arrangement as illustrated by FIGS. 1-3 comprises at least one main gas burner 10 and a pilot flame gas burner 11 mounted adjacent to the main burner. The pilot flame gas burner is supplemented by an automatic igniting device which comprises an ignitor 12 of some suitable conventional type, e.g. a spark gap connected with the energizing devices of the ignition arrangement as described further below. When a pilot flame is produced by the pilot flame burner 11 then this flame reaches not only the gas issuing from the nozzles of the main gas burner 10 but reaches also a thermocouple 13 which constitutes one portion of a conventional thermoelectric safety arrangement.

For placing the entire system into service and also for operating the system by remote control a main'switch 14 is provided in one of the supply lines 15, 16 which connect the arrangement with a supply of electric energy. As will be seen the arrangement is operated mainly by means of an electromotor which for the sake of clarity of the drawing is not fully illustrated but is symbolically represented by the circular symbol 20 in FIGS. 1-3.

This-motor circuit 20 is co-nnectable with the main. -supply line 15,16; via-the controlcontact sets 28 and 29, the

operation of which will be described further below.

When the electromotor 20 is in operation it'rotates a shaft, not shown, which carries a multiple .camarrangement 22 and ,an eccentric member e,g. a crank pin-'39.

repeatedly and consecutively open and close the ignition contacts 24 so as to produce in a wellknownmanner sparks across the spark gap, 12. The diametrically op- 1 posed lobe 27 servesto keep, while the cam disc 22 is The cam arrangement 22 cooperates with themotor switch 7 contacts 28 and the ignition control contacts 24' while scribed further-below. The operation of thee-rank pin 30 serves to operate the main gas-valve 36 and the pilot flame gas valve 21 in such a manner that starting from the idle position shown in FIG. lga rotation ofthe shaft, and of the crankpin through about 180 causes the pilot flame gas valve 21'to, open, During a portion of this.

rotation through 180 the (ignition switch contact 24' are actuated so as to energize the ignitor device 12' and to ignite :the gas issuing from the pilot flame gas' burner 11. A further rotation of the shaft and crank pinreturns the ca1n'arrangernent'22 to'its original starting position in which the pilot flame gas valve is given freedom to stay in open position or to return to closed position. 'If the pilotflame'gas valve21 is kept in open position by additional safety means described further below, then the main gas valve 36 is opened and the electromotor is stopped.

tion then also the main gasvalve 36 is again closed and theelectromotor is automatically restarted so. that the attempted igniting procedure is repeated.

In. the illustrated embodiment of the invention the multiple cam arrangement 22 consists of a single cam disc 22 provided at oneportion of its circumference with at least one, preferably a plurality of small lobes cooper: ating with a cam follower member attachedto the nearest oneof'the normally open motorswitch contacts 28, and with another lobe 27 located approximately diametrically opposite to the lobes 23 andalso cooperating with the above mentioned cam follower. As can be seen from FIGS. 1-3, closing of the motor switch contacts 28 causes also closing of the adjacentrignitionswitch contacts 24,.

while in the respectively opposite'position both switch contacts 24 and28 are simultaneously open. The crank pin 30 constitute the pivot for a rocking lever 31 which is in operative engagement at one 'of'its ends 32 with V the second pairof rnotor switch contacts 29, connected; 'in parallel withjthe contacts 28, is operated bythe main gas valve 36 or rather its valve stern-T35 as will be defor stopping the motor operation.

rotating the motor, switch contacts 28 closed and thus keeps ther'notor operating irrespective of whether the V motor. .For this reason-the contacts 29- are arranged in such a manner that they can lbe actuated by'the valve stem 34 of themain gas valve 36. As long as the main gas valve 36 is in closed position, the contacts'29 are also kept'in closed condition.

According to the invention the crank j pin serves 7 as pivot fori'a rocker lever 3 1"as mentioned above. The

v If,.however, the pilot flame gas valve ,21 is notkept'in open position but returns to its closed posithe valve stem 33 of the pilot flame gas valve 21 and atits other end 34 in operative engagement with the valve stem 35 of the main gas valve 36.

Of course, the multiple cam arrangement 22 may also consist of at least two cam discs arranged next to each rocker. lever 31 may be shaped or constructed in various ways. For instance, it may beprovided with a round bore concentric with its pivoting axis and fitting over the crank pin 30, while the two end. portions; 32 and 34 of the lever 31 are provided each with a longitudinal slot shaped to at least partly embrace a'portion' of the valve stem 33 of the pilot flame gas valve 21'or the valve st m 35 of the main gas valve;3, respectively, so as to be always in operative engagementtherewith. On the other hand, the preferred embodiment of the rocking-lever 31 as illustrated in the drawings consists in an elongated slot 37 in thecent'er portion of the lever 31, the width of this slot 37icorresponding to; thejdia'rneter of the crank pin 30 so that the lever 1 is supported by the pin 30 both pivotably and slidably. .On the other hand, at least one ofthe lever ends 32or 34'is also,;provided with a longitudinal slot or fork engaging aportion of one ofthe valve stems.33, or 35, the other lever end of the lever 31 engaging the other valve'stem in a similar manner In the preferred embodiment as fillustrated by FIG. 4; the end 32 0f the'rocking lever 31 is provided with a longitudinal slot or fork 38 engaginga portion of the valve stem arrangement33 of the pilot fiame'gas valve 21. It is an advantage of the illustrated arrangement of the invention that the engagement between the end 32 of the rocking other on the shaft which is driven by motor, one of these cam discs carrying on its circumference at least one lobe for actuating in the manner described above; the ignition switch contacts 24 while the other cam disc carries one lobe angularly oif-setabout 180 relative to thejust mentioned lobe'or lobes of the first cam disc serving for actuating the motor switch contacts 2 8 The preferred embodiment of the-invention as illustrated is equipped with aione-piece .cam disc 22 as described above. ,The ignitor 12may be constructedin the manner of a spark plug comprising a spark .gap which i cooperates Wuhan ignition transformer or ignition coil 25 having a secondary winding in circuit with the ignitor 12 while its primary is connected via the ignition switch contacts 24in circuit with th'e'energy supply lines15,

and 16, a capacitor 26 being connectable in parallel with the primary winding of the'ignition transformer-25 in a well known manner.. Instead of a spark gap ignitor 121 The valvechamber 45 is connected to a tubular duct 47 lever 31 and a portion of the valve stem 33 is located outside thegas control body,40 so that also the electromagnet device '39 can be located outside the body 40 inside the housing 52. i

As can beseen particularly from FIG.;4, the gas control body 40 is, provided with a gas inlet or pipe connection ,41 anda main gas outlet orpipe connection 42. The gas'inlet' 41 communicates with a mainvalve cham-. ber in which operates the main gas valve 36.which isurged by the spring 44 into closing positionwithare 'spect to the .valve seat 43; When the main valve 36 is open the chamber 45xcommnnicate's, with a main cham-, ber 46 thatjis in direct connection with thepou'tlet 42.

with anothe'r'valve chamber 48jin,which operates the pilot gas valve' '21 which is'urg edby spring 50 to closing position relative to the -valve'seat 49. The entire gas fcontrol body 40is tightly closed -ontop by acover plate 151. However, the valve stems 33? and 35 'of the above also other types of ignitors, e.g.,.an incandescent ignitor; cooperating with a suitable transformer, may beused As shown in the drawings, the circumference of :the cam. d1sc 22carries a plurality of small lobes which serve to mentioned valves extendthrough the 'cover plate 31 in upward'direction, the valve stems passing through the respective openings in a' 'gas-tightly sealed manner. In the space above ;the cover plate 51. are arranged the motor 20, not shown, the cam disc .22'with the lobes 23 and -27,*the crank pin 30, therocking lever 31, the switch contacts 24, 28and 29 and the electromagnet device 39.

The electrical connections, the ignition transformer 25 and the capacitor 26 are not shown in FIG. 4 for the sake of clarity. All the last mentioned elements and parts are accommodated within and protected by a housing 52. The electromagnet device 39 contains an electromagnet 54 energizable by a current furnished by the thermocouple 13 when the latter is heated by the pilot flame and when the relay switch 62 is in closed position. The purpose of the electromagnet 54 is to hold the pilot flame gas valve 21 in open position once it has been moved into that position provided that at such time the pilot flame feeds the thermocouple 13 and that the relay switch 62 is in closed position on account of the main switch 14 being in closed position. For enabling the elcctromagnet 54 to hold the pilot flame gas valve 21 in closed position the upper end 33' of the pertaining valve stem arrangement 33 is provided with an armature plate 53 opposite to the electromagnet 54. In order to cause the armature plate 53 to be pressed resiliently against the electromagnet 54 an elastic coupling is provided between the valve stem portion 33 and the valve stem portion 33". The elastic coupling comprises a bushing 55 which is operatively engaged by the fork 38 of the end 32 of the rocking lever 31. The upper valve stem 33' carrying a spring support plate 57 for an inner coupling spring 58 is axially movable through an opening in the upper closure of the bushing 55. The relative movement of the stem 33' with respect to the bushing 55 is limited by the action of the spring 58. The lower valve stem portion 33" is slidably movable through an opening in the lower portion of the bushing 55, its movement in outward direction being limited by a stop plate 59. The function of this coupling arrangement will be described further below. The other end 34 of the rocking lever 31 is operatively connected with the valve stem 35 in a manner not shown in detail, but so selected that an insulated extension 60 of the valve stem 35 extends in upward direction beyond the point of engagement between the lever end 34 and the valve stem 35. The extension 69 is adapted to engage the electromotor switch contacts 29 when the valve 36 is in closed position.

The valve springs 44 and 59 are so dimensioned that their joint forces acting on the rocking lever 31 are sufficient for overcoming, when necessary, the holding power exerted by the electromagnet 54 on the armature plate 53.

The operation of the entire arrangement is as follows:

FiG. 1 illustrates the control system in operative position. Therefore the main switch 14 is shown in open position and likewise a thermostat switch 61 arranged in the supply 15. The ignition switch contacts 24 as well as the motor switch contacts 28 are in open position while the other motor switch contacts 29 are held in closed position because the main gas valve 36 is in closed position. Also the pilot gas valve 21 is in closed position so that under the circumstances gas, as indicated by a dotted area exists only in the gas inlet and in the valve chamber 45, the connection duct 47 and in the second valve chamber 48.

The arrangement is placed into service by remote control thpough closing of the main switch 14, it being assumed that the precautionarily arranged thermostat switch 61 has also been placed in closed position. The current supplied to the lines 15 and 16 energizes first of all the coil of the relay switch 62 whereby a circuit between the thermocouple 13 and the electromagnet 54 is established. Simultaneously the electromotor 20 is started via the closed motor switch contacts 29 so that now the cam disc 22 as well as the crank pin start to rotate. At first the contacts 24 and 28 remain in open position. However the rotation of the crank pin 30 causes the rocking lever 31 to pivot from its starting position according to FIG. 1 toward a second position as shown in PEG. 2. Whereby the pilot flame gas valve 21 together with its valve stem arrangement 33 is lifted into open position so that now gas can flow from the chamber 48 to the pilot flame gas burner 11 and issue from its nozzle. However, the arrangement according to FIG. 4 provides for a certain delay between the start of the pivoting movement of the lever 31 and the actual opening of the valve 21. This is due to the fact that the bushing 55 must first be lifted by the pivoting movement of the rocking lever 31 until the stop plate 59 at the end of the lower valve stem portion 33" is engaged by the bottom of the bushing 55. This delay time is called the flushing time during which non-combusted gas that may exist in the apparatus, are permitted to escape before ignition takes place. As the pilot flame gas valve 21 is further lifted by the movement of the rocking lever 31 finally the armature plate 53 reaches the electromagnet 54 and is brought into resilient engagement therewith on account of the action of the spring 58 in the coupling bushing 55. The pilot fiarne gas valve 21 reaches its full opening position when the armature plate 53 is in engagement with the electromagnet 54 and when the cam disc 22 has carried out a rotation of about 180 during which the plurality of small cam lobes has acted on the contacts 24 and 28. Since the motor switch contacts 29 are still in closed position the temporary and alternating closing and opening of the contacts 28 has no effect. However, the repeated closing and opening of the ignition contacts 24 has the effect that the igniting arrangement comprising the ignitor 12 and the transformer 25.and capacitor 26 are actuated. The resulting sparks across the ignitor 12 ignite the gas issuing from the pilot flame burner 11 so that the resulting pilot flame heats the thermocouple 13. VVhereby a thermocurrent is produced which serves to energize the electromagnet 54 so that now the armature plate 53 and together with the latter also the pilot flame gas valve 21 will be held in open position as long as the pilot flame heats the thermocouple 13 and as long as the magnetic attraction of the armature plate 53 is not overcome by force.

As now the cam disc 22 continues its rotation the cam pin 34) also rotates so that the rocking lever 31 is forced to pivot because the valve stem arrangement 33 is held in lifted position. This pivoting of the rocking lever 31 causes the lever end 34 to open the main gas valve 36. Consequently the gas can now flow freely from the valve chamber through the central chamber 46 and through the outlet 42 to the main gas burner 10 where the gas issues from the main burner nozzles is not ignited by the pilot flame. The spaces occupied by gas in this operative condition of the arrangement are indicated in FIG. 3 by the dotted areas. Simultaneously with the opening of the main gas valve 36 the extension 60 of the valve stem 35 disengages from the motor switch contacts 29 so that the latter assume open condition and the electromotor is stopped after it has produced a full revolution of the cam disc 22 and of the crank pin 30. This position of the entire arrangement existing after the electromotor has been stopped is illustrated by FIG. 3 which therefore illustrates the conditions existing when the main burner 10 is in normal operation. In case that the thermostat switch 61 is opened for instance on account of the action of a room thermostat, then the current flow between the thermocouple 13 and the electromagnet 54 is interrupted by the de-energization of the relay switch 62. Consequently the pilot flame gas valve 21 will be closed under all circumstances and in particular the armature plate 53 will be separated from the electromagnet 54 by the action of the valve spring as well as the valve spring 44. However in this case also the main gas valve 36 is closed. Should for any reason the supply of electric energy through the lines 15 and 16 discontinue, the same effect takes place because also in this case the relay 62 is de-energized. Should, on the other hand, the gas supply fail, then first of all the flames of the main burner 10 and the pilot flame are extinguished so that the thermocouple 13 is no longer heated and consequently the electromagnet 54 is de-energized. As a result also in this case the armature plate 53 drops oh. and the pilot flame gas valve 21 as well as the main gas valve 36 move to closed position. The closing of the main gas valve 36 in all these cases also produces closing of the motor switch contacts 29 so that the whole system is again in readiness for startingthe operation of the electromotor as soon as for instance the thermostat switch 61 is closed again. However, should at the time of reclosing of the thermostat switch 61 gas not be available then the whole cycle of operations is repeated until after the return of the gas supply an ignition is effected.

If at any time an'appliance equipped with the control system is intended to be taken out of service, all that is necessary isto openthe main switch 14 wherever this main'switch maybe located for the purpose of remote 7 control. In this manner it is very easy to apply remote control to agas heated appliance or device becausemerely by operating the main switch 14 it'can easily be ignited or extinguished without any necessity of carrying out any control operation at the appliance itself.

It is evident that the control system according to the tromagnet means are energized and both of said valve invention can be applied in the samemanner to gas burners of any size and number as will be readily understood by those skilled in the art. a

It will be understood that each of the elements described above or two or more together, mayalso find a useful application in other types of a gas burner control system difle'ring from the types described above.

While the invention has been illsutrated and described as embodied in a gas burner control system comprising electrical and mechanical control elements, it is not intended to be limited to the details shown, since various modifications and structural changes'may be made without departing in any way'from the spirit of the present invention. a

Without further analysis the foregoing will so fully reveal the gist of the present invention that others can by applyingfcurrent knowledge readily adapt it for various applications without omitting features that, (from the standpoint of prior art, 'fa'irly constitute essential characteristics of the generic or specific aspects of'this invention and, therefore, such adaptations should and are intended to be'cornprehended within themeaning and range of equivalence of the following claims.

' Whatis claimeda-nd. desired to be secured by Letters Patent is: i

1. 'A gas, burner control system, comprising, in com-1 bination, gasinletmeans'; main gasburner means; a main gas valve arranged between saidgas inlet. means andsaid main gas burnerfmeans for controlling the flow of -gas to the latter; pilotjflame gas' burner means adjacentto said main gas burner means; a pilot flamegas valve arranged a between said gas 'inlet means and said pilot flame gas burner means forfcontrollingthe flow of gas to the latter; electrical igniting means adjacent to said pilot flame gas burner means forigniting a pilotlflame'when saidvigniting means are'energize'd while gasflo'wsthrough said pilot flame'gas valve to said pilot flame gas'burner means; in circuit withsaid ignitor means for energizing' the'latter; electric valve control means including 'electromagnet means for "holding when energizedsaidl pilot flame gas valve in openfpositionfome the latter'has been moved to open position, and thermoelectric means. responding to exposure to theheat of said pilotflame by energizing said eIeQtromagnetmetins seats to hold said pilot flame gas valve'open as long as there is a.pilot flame; and control means for controlling said maingasvalve and said pilot flame gas valve and said igniting means, including electromotor means, ignitionswitch means in circuit with said;

igniting means for controllingthe latter, rotarycam means rotatable by saidl'electromotorrmeans .and actuating in diflerentrot'ationa'l positions said motor and ignition switch means, respectively, a mechanical actuating member cooperating with both said. main gas valve'and said pilot flame gas valve and movable by said electromotor means between a plurality of 'positions, in one of which positions saidactuating-member places both said main gas valve and means are in said open position.

2. A gas burner control system, comprising, in combination, gas inlet means; main gas burner means; a main gas valve arranged between-said gas inlet means and said main gas burner means for controlling the flow of gas to the latter; pilot flame gas burner'means adjacent to said main gas burner means; a pilot flame gas valve ar ranged between said gas inlet means and said pilot flame gas burner means for controlling the flow of gas to the latter; electrical igniting means adjacent to said pilot flame gas burner means for igniting a pilot flame when said igniting means are energized while gas flows through said pilot flame gas valve to-said pilot flame gas burner means; energizing means incircuit with said igniter means for energizing the latter; electric valve control means including electromagnet means for holding when energized said pilot flamexgas valve in open position once the latter I has been moved to open position, and thermoelectric means responding to exposure to the heat of said pilot flame by energizing said electromagnet means so as to hold said pilot flame gas valve open as long as there is a .ilot flame; control means for controlling said main gas valve. and said pilot'flame gas valve and saidigniting means, including electromotor means, motor switch'mearis in circuit with said electromotor means for controlling the latter, ignition switch means in circuit with said igniting means forcontrolling the latter, rotary cam means rotatable by said electromotor means and actuating in different rotational positions said motor and ignition switch means, respectively, eccentric means rotatable by I said electromotor means jointly with said cam means, and

a rocking lever means cooperating with both said main gas valve and said pilot flame gas valve and pivotable about said eccentric meansasthe latter is rotated by said electromotor means between a plurality-of positions, in

one of whichpositions said actuating member places both said main gas valve and said pilot flame gas valve in closed position, in asecond one of which positions said gas valve including a valve plate, and a valve stem and 1 arranged between said gas inlet means and said main gas burner means forcontrolling the flow of gas to the latter; pilot flame gas burner means adjacent to said main gas burner means; a pilot flame gas valve-including a valve 7 plate and a valvestem and arranged between said gas inlet means and said pilot flame gas burner means for controlling the'flowtof gas to thelatter; electrical igniting meansadjacent-to said pilot flame gas burnermeans for igniting a pilot flame whe'n said igniting means are energized while gas flows through said pilot flame gas valve tosaid pilot flame .gas burner means; energizing means in circuit with said ignitor means for energizing the latter;

electric valve control means including electromagnet meanstfort holding when energized said pilot flame gas valve inv open position once the latterthas been moved to open position, and thermoelectric means responding to exposure to the heat of said pilot flame by energizing said electromagnet means so as to hold said pilot flame 9 gas valve open as long as there is a pilot flame; and control means for controlling said main gas valve and said pilot flame gas valve and said igniting means, including electromotor means, motor switch means in circuit with said electromotor means for controlling the latter, ignition switch means in circuit with said igniting means for controlling the latter, rotary cam means rotatable by said electromotor means and actuating in different rotational positions said motor and ignition switch means, respectively, eccentric means rotatable by said electromotor means jointly with said cam means, and a rocking lever means operatively connected near one end thereof with said valve stem of said main gas valve and near its other end with said valve stem of said pilot flame gas valve and pivotable about said eccentric means as the latter is rotated by said electromotor means between a plurality of positions, in one of which positions said actuating member places both said main gas valve and saidtpilot flame gas valve in closed position, in a second one or" which ositions said actuating member places said pilot flame gas valve in open position while leaving said main gas valve closed, and in a third one of which positions said actuating member places both said main gas valve and said pilot flame gas valve in open position.

4. A gas burner control system, comprising, in combination, gas inlet means; main bas burner means; a main gas valve including a valve plate and a valve stem and arranged between said gas inlet means and said main gas burner means for controlling the flow of gas to the latter; pilot flame gas burner means adjacent to said main gas burner means; a pilot flame gas valve including a valve plate and a valve stem and arranged between said gas inlet means and said pilot flame gas burner means for controlling the flow of gas to the latter; electrical igniting means adjacent to said pilot flame gas burner means for I igniting a pilot flame when said igniting means are energized while gas flows through said pilot flame gas valve to said pilot flame gas burner means; energizing means in circuit with said igniter means for energizing the latter; electric valve control means including electromagnet means for holding when energized said pilot flame gas valve in open position once the latter has been moved to open position, and thermoelectric means responding to exposure to the heat of said pilot flame b energizing said electromagnet means so as to hold said pilot flame gas valve open as long as there is a pilot flame; and control means for controlling said main gas valve and said pilot flame gas valve and said igniting means, including electromotor means, motor switch means in circuit with said electromotor means for controlling the latter, and including first switch means operable by said valve stem of said main gas valve so as to be in closed position as long as said main gas valve is in closed position, and second switch means connected in parallel with said first switch means so as to interrupt the electromotor circuit when both said valves are in open position, ignition switch means in circuit with said igniting means for controlling the latter, rotary cam means rotatable by said electromotor means and actuating in different rotational positions said second switch means and ignition switch means, respectively, eccentric means rotatable by said electromotor means jointly with said cam means, and a rocking lever means operatively connected near one end there of with said valve stem of said main gas valve and near its other end with said valve stem of said pilot flame gas valve and pivotable about said eccentric means as the latter is rotated by said electromotor means between a plurality of positions, in one of which positions said actuating member places both said main gas valve and said pilot flame gas valve in closed position, in a second one of which positions said actuating member places said pilot flame gas valve in open position while leaving said main gas valve closed, and in a third one of which positions said actuating member places both said main gas valve and said pilot flame gas valve in open position.

5. A gas burner control system, comp-rising, in combination, gas inlet means; main gas burner means; a main gas valve including .a valve plate and a valve stem and arranged between said gas inlet means and said main gas burner means for controlling the flow of gas to the latter; pilot flame gas burner means adjacent to said main gas burner means; a pilot flame gas valve including a valve plate and a valve stem and arranged between said gas in- -let means and said pilot flame gas burner means for controlling the flow of gas to the latter; electrical igniting means adjacent to said pilot flame gas burner means for igniting a pilot flame when said igniting means are energized while gas flows through said pilot flame gas valve to said pilot flame gas burner means; energizing means in circuit with said igniter means for energizing the latter; electric valve control means including electromagnet means for holding When energized said pilot flame gas valve in open position once the latter has been moved to open position, and thermoelectric means responding to exposure to the heat of said pilot flame by energizing said electromagnet means so as to hold said pilot flame gas valve open as long as there is a pilot flame; and control means for controlling said main gas valve and said pilot flame gas valve and said igniting means, including electromotor means, motor switch means in circuit with said electromotor means for controlling the latter and including first switch means operable by said valve stem of said main vgas valve so as to be in closed position as long as said main gas valve is in closed position, and second switch means connected in parallel with said first switch means so as to interrupt the electromotor circuit when both said valves are in open position, ignition switch means in circuit with said igniting means for controlling the latter, first and second rotary cam means jointly rotatable by said e-lectromotor means, said first cam means actuating in at least one first rotational position said ignition switch means and said second cam means actuating said second switch means in a second rotational position angulanly up to about 180 offset against said first rotational position, eccentric means rotatable by said electromotor means jointly with said cam means, and a rocking lever means opera-tively connected near one end thereof with said valve stem of said main gas valve and near its other end with said valve stem of said pilot flame gas valve and pivotable about said eccentric means as the latter is rotated by said electromotor means between a plurality of positions, in one of which positions said actuating member places both said main gas valve and said pilot flame gas valve in closed position, in a second one of which positions said actuating member plaices said pilot flame gas valve in open position while leaving said main gas valve closed, and in a third one of which positions said actuating member places both said main gas valve and said pilot flame gas valve in open position.

6. A gas burner control system, comprising, in combi nation, gas inlet means; main gas burner means; a main gas valve including a valve plate and a valve stem and arranged between said gas inlet means and said main gas burner means for controlling the flow of gas to the latter; pilot flame gas burner means adjacent to said main gas burner means; a pilot flame gas valve including a valve plate and a valve stem and arranged between said gas inlet means and said pilot flame gas burner means for controlling the flow of gas to the latter; electrical igniting means adjacent to said pilot flame gas burner means for igniting a pilot flame when said igniting means are energized while gas flows through said pilot flame gas valve to said pilot flame gas burner means; energizing means in circuit with said igniter means for energizing the latter; electric valve control means including electromagnet means for holding when energized said pilot flame gas valve in open position once the latter has been moved to open position, and thenmoelectric means responding to exposure to the heat of said pilot flame by energizing said electromagnet means so as to hold said pilot flame gas valve open as long as there is a pilot flame; andcontro means foncontrolling said main gas valve and said .pilot flame gas valve and saidigniting means, including electromotor means, motor'switch means in circuit with said electromotor means for;controlling the latter and 'in cIuding first switch means operable by said valve stem of said 1 main gas valve so as to bein closed positionaslongas said main gas 'valve is in closedposition,-and-second 1 switch "means-connected; in parallel with said-first switch means so asito interrupt the 'electromotor-circuit'when means in circuit with said ignitingi'means for-controlling the latter, multi-lobe rotarycam means rotatahleby said .-electromotormeans, at least one first lobe actuating in one first rotational position said ignition-switch means and both said ivalves are in open position, ignition switch? 9iated ;therewith. l 5

a second lobe actuating said second switch means in a 1 second rotational position angularly up to aboutlSO? off set against ,said first positionand actuatingtin different rotational positions'said second switch meansand ignition switch means,:respectively, eccentric means rotatable by saidelectromotor means jointly with said cam means, and a rocking lever meansoperatively connected nearcne end llh6IC0flWlth.I-S2lld valve stem of said main gas valve'and near its other end with said valvestemof said-pilot flame.

' gas valve and pivotableabout said eccentric means as the latter is rotated by said electromotormeans between a plurality of positions,'in one of which positions said actuating member, places both' saidnrain gas valve and said pilot flame gasvalve in o'losedposition, in a'second one of which positions'said actuating mernlber placessaid pilot flame gas valve in'open position whi'le leaving said;

main gas valve closed, and in afthird'one of whichpositio-ns said actuating member places :both said main gas valve and said pilotflame gas valve in*open. position.

7. A'gas burner controlssystem .as; claimed infolaim 4, wherein'said eccentric means' includes arotat-ablecrank' pin, and wherein said rocking lever means isgpivotaibly mounted 'onsaid crank pin,,said-endsoi said rockinglever 7 means. being slotted in radial direction andemb-racing 'a portion of said valve stems, respeotively,ijfor transmitting motion therebetween. a L 'i 8. A gas burner control systemlasiclai ned i'n'claim 4,

wherein:saidieccentric means includes azrotatable crank pin, and wherein said rocking lever means provided with an elongated slot slidingly and pivotably engaging said crank pin. 9. A gas burner'control composed 'of two coaxial .parts, one ofsaid parts'being attached to the valve plate thereof, the. other part .ineluding an armature plate cooperating with said electromagnet means, an elastic coupling axially slidable on both 7 said parts within predetermined limits being provided for electrically coupling said two parts together,said one end of said rocking lever system as "claimed in claim 3, I

wherein said valve stem of'said pilot-flame gas valve is a t in first switch means when said main gas valve is in closed position. p '11, -A gas burner control 'system as claimed in claim 1,

wherein said main gas valvevinclude si an elastic member tending to hold said main gas valve inlclosed position, and

.wherein said pilot flame gas 'valve includes an elastic member tendingjto hold said pilot flame gas valve'in closed position, said elasticmembersybeingso dimensioned that their combined forcesexerted in operation are sufficient for overcoming the :holding eifectzof said electromagnet means and thussfor separating saidrpilot flame gas valve fromisaid electroinagnet means for permitting said ranged between said gas inlet means and sa-idfpilot flame gas burner means'for controlling the flow of gas to the latter; electrical igniting means adjacent vto said pilot flamegas burner means for igniting a'pilotrflame vwhen said igniting means are energized while gas flows through said pilot flame gas valve to said pilot flame gas burner ymeans; energizing meansin circuit with said ignitor means "for energizing the latter; electric valve contr-olmeansineluding electromagnet means'for-holding when energized said pilot flame gas valve in open position once the latter has been moved tottopen position, and thermoelectric means responding to-exposureto-the heat of said pilot flame-byenergizing' said electromagnet means so as to holdsaid pilot fiame gas valve open as long as therefis a pilot flame; and eontrolmeans for controlling said main gas valve, said pilot flame gas valve, and'said ignition .means and including drive means, actuatingmeans operated by said drive means and operatively connected to said pilot flame, gas valve, said ignition means and said main gasvalve for sequentially opening said'pilot flame gas valve, energizing said ignition means and opening said mam gas valve, and means cooperating with said actuating means andjoperativelylconnected to said drive means for maintaining the latter in operation until both'of said valve means are open and said ignition means'has ignited the ,pilot flame, so thatsaid drive means will continue to op- "erate said actuating-means and the latter repeat the sequence of operations-until ignitionof the pilot flame has 10. A gas-burner control system asclaimed inclai'rn4, wherein said valve stem of said main gasrvalverincludes an extension beyond the point Where itis operatively engaged by the respective end of said rocking lever'means,

saidextension being arranged to engage and acuate said means operatively engaging said electric-coupling,

heen effected while both valve means are :open.

V Ref er ences'Cited by the Examiner Q UNITED STATES PATENTS 1,631,348 6/27 2,705,532 ,4/55 Thornbery'l; 158 -124 x 1,917,062 12 59 'Schuchardt- 159'131:X ,9 4,049 '12/60 Deverse a 1ss -131YX JAMES WESTIHAVER, Primary:Examiner. MEYER PERLlN, Exq min'er.- 

1. A GAS BURNER CONTROL SYSTEM, COMPRISING, IN COMBINATION, GAS INLET MEANS; MAIN GAS BURNER MEANS; A MAIN GAS VALVE ARRANGED BETWEEN SAID GAS INLET MEANS AND SAID MAIN GAS BURNER MEANS FOR CONTROLLING THE FLOW OF GAS TO THE LATTER; PILOT FLAME GAS BURNER MEANS ADJACENT TO SAID MAIN GAS BURNER MEANS; A PILOT FLAME GAS VALVE ARRANGED BETWEEN SAID GAS INLET MEANS AND SAID PILOT FLAME GAS BURNER MEANS FOR CONTROLLING THE FLOW OF GAS TO THE LATTER; ELECTRICAL IGNITING MEANS ADJACENT TO SAID PILOT FLAME GAS BURNER MEANS FOR IGNITING A PILOT FLAME WHEN SAID IGNITING MEANS ARE ENERGIZED WHILE GAS FLOWS THROUGH SAID PILOT FLAME GAS VALVE TO SAID PILOT FLAME GAS BURNER MEANS; IN CIRCUIT WITH SAID IGNITOR MEANS FOR ENERGIZING THE LATTER; ELECTRIC VALVE CONTROL MEANS INCLUDING ELECTROMAGNET MEANS FOR HOLDING WHEN ENERGIZED SAID PILOT FLAME GAS VALVE IN OPEN POSITION ONCE THE LATTER HAS BEEN MOVED TO OPEN POSITION, AND THERMOELECTRIC MEANS RESPONDING TO EXPOSURE TO THE HEAT OF SAID PILOT FLAME BY ENERGIZING SAID ELECTROMAGNET MEANS SO AS TO HOLD SAID PILOT FLAME GAS VALVE OPEN AS LONG AS THERE IS A PILOT FLAME; AND CONTROL MEANS FOR CONTROLLING SAID MAIN GAS VALVE AND SAID PILOT FLAME GAS VALVE AND SAID IGNITING MEANS, INCLUDING ELECTROMOTOR MEANS, IGNITION SWITCH MEANS IN CIRCUIT WITH SAID IGNITING MEANS FOR CONTROLLING THE LATTER, ROTARY CAM MEANS ROTATABLY BY SAID ELECTROMOTOR MEANS AND ACTUATING IN DIFFERENT ROTATIONAL POSITIONS SAID MOTOR AND IGNITION SWITCH MEANS, RESPECTIVELY, A MECHANICAL ACTUATING MEMBER COOPERATING WITH BOTH SAID MAIN GAS VALVE AND SAID PILOT FLAME GAS VALVE AND MOVABLE BY SAID ELECTROMOTOR MEANS BETWEEN A PLURALITY OF POSITIONS, IN ONE OF WHICH POSITIONS SAID ACTUATING MEMBER PLACES BOTH SAID MAIN GAS VALVE AND SAID PILOT FLAME GAS VALVE IN CLOSED POSITION, IN A SECOND ONE OF WHICH POSITIONS SAID ACTUATING MEMBER PLACES SAID PILOT FLANGE GAS VALVE IN OPEN POSITION WHILE LEAVING SAID MAIN GAS VALVE CLOSED, AND IN A THIRD ONE OF WHICH POSITIONS SAID ACTUATING MEMBER PLACES BOTH SAID MAIN GAS VALVE AND SAID PILOT FLAME GAS VALVE IN OPEN POSITION, AND MOTOR SWITCH MEANS IN CIRCUIT WITH SAID ELECTROMETER MEANS FOR MAINTAINING SAID ELECTROMETER MEANS ENERGIZED AS LONG AS SAID MAIN GAS VALVE IS IN SAID CLOSED POSITION AND FOR DEENERGIZING SAID ELECTROMOTOR MEANS WHEN SAID ELECON AND TROMAGNET MEANS ARE ENERGIZED AND BOTH OF SAID VALVE MEANS ARE IN SAID OPEN POSITION. 